Development of a sieverts-type apparatus with enhanced automation using a dual-valve pressure control device for solid state hydrogen storage applications

High-pressure volumetric sorption analyzers, commonly referred to as Sieverts-type apparatuses, offer precise measurements of absorption capacity, kinetics, pressure-composition isotherms (PCI), thermodynamic properties, and cyclic stability for materials utilized in hydrogen storage research. Although advanced commercial systems are available, their design or cost often limits measurement flexibility or accessibility, prompting many research groups to develop their self-built alternatives. However, achieving precise gas pressure/flow control, as well as complete automation, remains a challenge, as existing methods often require manual intervention and present opportunities for further optimization. This study tested a novel integration of a Pressure Control Device (PCD) into a self-built Sieverts-type apparatus, aiming to automate key aspects of hydrogen dosing and pressure control in hydrogen absorption measurements. The PCD was incorporated into the design and subsequently assembled. The system was volume-calibrated and used to evaluate the hydrogen storage capacity, kinetics, PCI, and cyclic stability of a known composite material consisting of commercial MgH ₂ powder (>98% purity) doped with 1 wt% commercial carbon-coated nickel nanoparticles. Additional kinetic and cycling stability tests were conducted using LaNi ₅ to demonstrate the system's applicability to different classes of metal hydrides. Our test proved to be a viable and cost-effective alternative for retrofitting self-built systems, facilitating the measurement of hydrogen-absorbing materials. Integrating a PCD streamlines measurement operations, improves reproducibility, and reduces manual handling and other time-consuming tasks.